A cable anchor is installed in a rock hole, by anchoring a distal end of the anchor within the hole. Then, to an end section protruding from the rock hole, a barrel and wedge assembly is attached or pre-attached. The cable anchor is then typically tensionably applying a tensioning force to this end section, to place the anchor body in pre-tension. Thereafter, the barrel is wedged against a faceplate to hold the body in pre-tension.
The distal end of the cable anchor can be mechanically anchored within the rock hole. Alternatively, the distal end can be anchored with a grout or resin.
The anchor process includes first inserting an adhesive containing capsule into the rock hole, followed by the cable anchor. Then, the cable is spun about its longitudinal axis, by engaging a suitably adapted drive means to a protruding or proximal end of the cable anchor. Once the capsule is torn to release its adhesive content, the drive means is removed and a tensioner attached. The tensioner tensions the cable anchor, now fixed in the rock hole by the hardened adhesive, and held in tension by the pre-attached barrel and wedge system. The tensioner is then detached and most of the end section of the anchor, which protrudes past the barrel and wedge, is cropped to prevent it from being safely taken off.
The process described above is disadvantageous in that a number of devices are used which have to be attached and removed from the cable anchor.
The disadvantage with this process is that, not only is the tensioning and cropping equipment is heavy and therefore difficult and cumbersome to elevate to the hanging wall of an excavation, where typically cable anchors are installed in a mining environment.
Also, it is difficult to have control over the length of cable anchor body that is cropped. The length of protruding cable is an important indication of proper cable installation.
To ensure that an installed cable anchor provides sufficient support to the rock mass within which it is installed, a predetermined length of the cable anchor must be inserted into the rock hole to extend, in tension, the length of the hole. If the hole is insufficiently deep, a cable anchor installed in this hole will have a longer protruding end section.
However, should a mine worker wish to cover up the fact that the rock hole is of insufficient depth, and the installed cable anchor of inadequate support, he merely has to crop the protruding end section after tensioning.
The invention at least partially solves the aforementioned problems.